1. Field of the Invention
This invention relates generally to electro-plating and more specifically, to selective plating of discrete areas of workpieces with noble metal.
2. Description of the Prior Art
In certain manufacturing, such as in connection with contacts for electrical connectors, precious metals are used to insure the contact characteristics. Moreover, the use of precious metals demands conservative processing for obvious economic reasons.
It is well known to control the depth of immersion of a workpiece into a plating bath in order to plate only that part which is submerged. However, if it is required to limit the plating on a part of the workpiece as a band spaced from the immersed lower extremity, it is then necessary to mask this lower extremity according to known techniques. Solid masking material or some form of aperture defining assembly may be used, but such measures must be applied prior to immersion of the workpiece in the bath, and subsequently removed after the plating operation has been carried out. The additional labor, care and quality control expense is an obvious disadvantage. The manner in which the unique method and means of the present invention solve this problem will be evident as this description proceeds.